That day in 1972, the nine men of B Company were roused by the sound of a mortar shell exploding outside the mudbrick house they lived in. They were preparing to pull out after months in the desert spent building relations with the locals, training their fighters and carrying out patrols.
The 5.30am explosion sent Cole scrambling to the roof of the house, where the group had a machine gun tucked behind sandbags.
The fast-firing weapon was one of three heavy weapons at the small base, set outside the village. They had another, older, machine gun intended for anti-air combat - which was only able to fire a few shots at the time before swinging skywards - and a couple of mortars.
About 640m away was a World War II-era 11.5kg gun designed to engage targets several kilometres away.
Rebel fighters emerged from the mist from about 500m away, carrying AK47 automatic rifles. Hidden from view was a maze of wadis, deep trenches carved into the desert by water, which meant the enemy could move freely about without being seen.
Cole opened fire, dropping about 10 to 15 men - he ran the machine gun back across the bodies to make sure they would not be fighting back.
The Battle of Mirbat had begun. It continued for the next five hours as wave after wave of rebels attacked the SAS men.
Cole said there was no time for fear. "All you could do is concentrate on the second or half a minute in your life ahead and see what you can do."
The battle raged without pause for hours. Cole's machine gun and the light artillery gun manned by Fijian-born trooper Corporal Talaiasi Labalaba were the pivots on which the SAS men's survival hinged.
The 11.5kg gun needed a minimum crew of four - but Labalaba fired it himself for more than an hour.
There was no trajectory or elevation calculations for distant targets. He fired it into the rebels over open sights, as if it were a massive rifle.
When he went down, fatally wounded, it was his Fijian mate Sekonaia Takavesi who sprinted through heavy fire to keep the gun firing. (Eight years later, Takavesi was among British special forces who mounted a raid on the Iranian Embassy in London, where 26 hostages had been held captive by six Iranian gunmen for five days. After the gunmen killed one of the hostages and threw the body on to the street, the SAS abseiled down from the building's roof in daylight and stormed through the windows.)
The two men kept the gun firing until Labalaba was hit again. When Takavesi was also wounded, others needed to take charge of the gun pit and keep the heavy weapon firing.
This time it was commanding captain Mike Kealy and Cole's mate Tommy Tobin who made the run through a stream of rebel fire. They reached the gun, where Tobin was also shot, receiving wounds from which he would die three months later.
While the men called for airborne help, the locals at the nearby village also chipped in. From the roofs of houses inside the compound, old men with aged .303 rifles fired at the rebels.
Cole greased up his machine gun with margarine, keeping it lubricated as he fired hundreds and hundreds of bullets into the oncoming soldiers.
"It changed my life forever. It made me think that there weren't too many problems in life when you went through something like that."
Now, he says he respects the rebels' determination to continue the attack. Then, he couldn't understand how they kept coming - and dying - in the face of unrelenting fire.
When help came, Cole was forced to take his own chances with heavy machine-gun fire. Despatched to set off a flare to guide in the casualty-evacuation helicopter, he watched the chopper fly off under enemy fire which quickly turned on him.
Expecting to be hit any second, he belly-crawled more than 100m back to the mud house.
When help came again, it was in the form of two jets from the Sultan of Oman's air force. The first strafed the battlefield and was hit, leaving the second to make repeated runs. The jets made a critical difference in taking pressure from the men.
However, the weight of numbers was telling. Kealy found himself in danger of being overrun, with rebels closing in on the gun pit. Kealy and wounded Takavesi fought them away until, in desperation, the officer called in a mortar strike on his own position.
The rebel attack was stalled. Dead and wounded littered the ground.
About 10am, Cole counted his bullets and told a mate he had 17 left from the thousands he had started with at dawn. Even today, almost 40 years on, locals are picking lead out of the dirt.
It was then the SAS troopers spotted a group of men approaching the battlefield, but this time from the other direction. They were soldiers sent to reinforce the SAS and Cole can still remember the intense feeling of relief at the sight of them.
Now he wants others to know about the secret battle he survived - because of the two men who did not.
Cole says the "faceless warriors" of Whitehall spurned the men who died - neither Labalaba nor Tobin received the recognition they deserved.
Labalaba was "mentioned in despatches" - the lowest form of honour and a failed tribute to a man who fought so courageously. Tobin got nothing for his miracle run through a shower of bullets.
Cole broke the code of silence to champion these men for a posthumous Victoria Cross. Rourke's Drift, to which this battle is compared, saw 11 VCs awarded. Over two days in January 1879, 150 British soldiers held off 4000 Zulus attacking a supply station next to the Tugela River in Natal Province, South Africa.
But in the 1970s, the secrecy of Britain's war meant that not only was the battle hushed up but so was the bravery of his friends, said Cole.
But in his family, the story has never been a secret. A painting of the battle has hung on his wall for years, spurring questions from children and grandchildren.
The day before the battle, Cole wrote home to his wife. In the letter, he raised the prospect of starting a family.
"That baby is now 38 years old, called Gareth and living in Papamoa beach," says Cole. There are three children there - "real Kiwi kids", he says with pride - who will grow up knowing about the Battle of Mirbat.
Cole hopes to join them next year. His application for residency is in. The house in Gloucestershire is renovated and is on the market.
